A common method to use and store magnetic recording tape is the cassette. Typically, the cassette has an enclosure with two tape reels. During use the tape is transported from one reel to the other past one or more recording or playback transducers. Cassettes are useful for storing tape in an easily retrievable manner, since they can be easily labeled on one or more surfaces and many cassette formats can be arranged with at least part of the labels visible on a spine similar to arranging books on a shelf.
However, it is often desirable to provide a protective enclosure, such as a box or case, to store or transport the cassette. Such boxes are called album or library boxes. Because the album box encloses the cassette, it becomes necessary to provide some device, such as labeling an outer surface of the album box, to describe the contents of the stored cassette. Since an album box may contain different cassettes at various times, it is desirable for the label on the box to be easily changed to correspond to the stored cassette.
One way to change labels on an album box is taught in U.S. Pat. No. 4,717,021. Transparent film panels are attached to the outer surfaces of the box to form transparent pockets for receiving labels. Another known box uses a single pocket wrapped around the box spine and front cover. With these boxes, errors in matching cassettes to boxes can occur if the correct cassette is not placed in the box carrying its label. Moreover, this labeling system requires labels to be created both for the cassette and for the box.
U.S. Pat. No. 4,555,021 discloses a simpler way to provide a labeled container for a cassette. An album box is made of a transparent material, so that the cassette label can be viewed through the box wall. To allow only the label to be visible, the nonwindow portions of the box are textured to reduce the transparency of the surface. However, this box requires significant effort to assemble, and is not as aesthetically pleasing because it is made of a flat blank which must be folded into the shape of an album box.
A cassette box having a separately formed window inserted into an aperture in an opaque wall of the box is disclosed in U.S. Pat. No. 4,501,359. These boxes are difficult to produce at the low cost levels required for packaging, due to the separate assembly operation for the window.
U.S. Pat. No. 5,277,308 discloses a cassette container made entirely of transparent polymeric material, except for the door which is made of a living hinge material. This container suffers from using large quantities of transparent molding materials. Durable transparent polymers tend to be more expensive than commonly available non-transparent materials.
Japanese Published Patent Application No. 05-042562 discloses an injection molded container for a cassette which uses transparent material for the window portions and an opaque material for the remainder of the container. This container is produced by a two-shot molding process. A sliding core is inserted into the mold cavity to form the window aperture while molding the opaque portion of the container. After the opaque portion has been formed, the sliding core is removed from the window aperture area and transparent molding material is injected to form the window. This two-shot molding is more difficult and expensive than one-shot molding, and the ability to perform two-shot molding is not widely used in the packaging industry.
In view of the disadvantages of the existing album boxes and available methods of fabrication, there is a need for a more easily produced opaque cassette container having at least one transparent window.